Yet it’s interesting how Blizzard invaded with their Heroes Of The Storm and Overwatch. I don’t know the stats but looks like they actually dragged some audience from Team Fortress and other MOBA games (some of my friends are among the latter). I could rationalize that these games attract people so much becase Blizzard is known to be tough with cheaters and having better anticheats than Valve, because HOTS is a casual MOBA with relatively short matches and no items to be bought but only skills, etc. But i don’t know.
Maybe it’s because games rust. You cannot update forever, keeping up with modern demands on graphics quality and others. And people will someday feel tired of game mechanics.